An advanced copy function is known as an example of a function of a storage device. An advanced copy function is a function that implements the backup of data of a work volume with firmware of a storage device without using the resources of a server (a host). One point copy (OPC) function and Quick OPC function are known as examples of the advanced copy functions. The OPC reproduces all of the data of a work volume in snapshot form at a predetermined timing. Like the OPC, the Quick OPC creates a reproduction of all of the data of a work volume at an initial backup, and copies updated portions (different portions) at a second backup and onwards.
There are cases where a work volume, which corresponds to a backup source, and a backup volume, which corresponds to a backup destination, are managed as virtual volumes. A virtual volume is a virtual logical volume. A portion of regions of a physical resource are dynamically allocated from a storage pool to a virtual volume depending on access from a server. Thin provisioning is known as an example of a function that allocates effective physical regions to such a virtual volume.
In thin provisioning, a virtual volume can make a server recognize a virtual storage capacity, which differs from a storage capacity of a physical region that is effectively allocated. Further, a storage resource that is effectively allocated to a virtual volume can also be set to a requisite minimum. A physical region of a virtual volume is dynamically allocated when data from a server is written to the virtual volume. The unit of the allocation of physical regions is a segment of one or more disk drives within a storage system, or the like. Meanwhile, in a case where an unnecessary region arises in a virtual volume as a result of data being deleted, or the like, the allocation of the physical region thereof is removed. The removal of the allocation of such a physical region is, for example, performed by issuing an execute instruction of an UNMAP command or formatting of a volume.
With respect to the backup of data, various items of the related art are known.
For example, with respect to a certain item of the related art, an information backup/restoration process device configures a device driver that performs filtering of an I/O of a virtualized volume, which corresponds to a backup destination on a host device side. Further, the information backup/restoration process device cooperates with a mounted file system, and performs a process so that only a portion of a sector region that is being used as a file is READ and WRITTEN. As a result of this, the information backup/restoration process device realizes the READING and WRITING of only a portion desired for backup on the virtual volume.
In another technique, a storage control device refers to writing management information, which is information for managing where on one or more related first storage devices writing of a plurality of segments has occurred. As a result of this, the storage control device specifies one or more locations in the one or more first storage devices at which writing has occurred, and performs backup of one or more data elements in the second storage device, which are respectively stored in the specified one or more locations.
In still another technique, in addition to a storage system control module, a management server and a backup server, a storage system includes one or more virtual volumes and a virtual file system. Each virtual volume is represented as a virtual file within the virtual file system. In this instance, each virtual file represents data that is effectively saved within a virtual volume. The storage system control module is configured in a manner that facilitates a backup operation of a selected virtual volume. The operation includes a step of accessing the virtual file system of the storage system, and a step of reading a virtual file that corresponds to a selected virtual volume. The storage system control module is configured in a manner that facilitates a restoration operation of a selected virtual volume. The operation includes a step of accessing the virtual file system of the storage system, and a step of creating a virtual file that represents a selected virtual volume.
Japanese Laid-open Patent Publication No. 2010-86474, Japanese Laid-open Patent Publication No. 2008-181271, and Japanese Laid-open Patent Publication No. 2010-231770 are examples of the related art.